Indicator cap assembly



June 16, 1959 T. w. JENTGES INDICATOR CAP ASSEMBLY Filed Dec. 9, 1955n'caj INVENTOR, v

THOMAS w. JENTGES #1 TTbRNEY- United States Patent Ofl 2,890,538Patented June 16, 1959 ice INDICATOR CAP ASSEMBLY Thomas W. Jentges,Anaheim, Calif., assignor to Marco Industries Company, Beverly Hills,'Califi, a corporation of California Application December 9, 1955,Serial No. 552,176

1 Claim. (Cl. 40--130) This invention relates to indicator lights of thetype used on instrument panels (e.g. in aircraft) for indicating variousoperational functions of the apparatus to which the instrument panel isappurtenant. In some applications, the lens of such an indicator lightmay usefully bear directional indicia such as an arrow or equivalentdirection indicating device. More commonly, the indicator lens bears alegend which must be upright in order to be satisfactorily read. Thegeneral object of this invention is to provide a very simple yeteifective lens mounting head providing for rotary adjustment of such alens for correct orientation of the legend or indicating character onthe lens.

A further object is to provide for such adjustment by finger tipoperation, and with maximum ease.

Other objects will become apparent in the ensuing specification andappended drawing in which:

Fig. 1 is a plan view, partially in horizontal section, of an indicatorlight embodying the invention;

Fig. 2 is an end view of the same;

Fig. 3 is a perspective view of the washer spring component thereof; and

Fig. 4 is a sectional view of a modified form of the invention.

Referring now to the drawing in detail, I have shown, as an example ofone form in which the invention may be embodied, an indicator lightadapted for mounting in a panel 5 which may be an instrument panel (e.g.of an airplane). The light comprises generally a lamp-housing barrelassembly 6 and a lens assembly 7, commonly referred to as the head ofthe device.

Barrel assembly 6 comprises an outer barrel or shell 8, externallythreaded for convenient mounting in panel 5 by projecting it through anaperture 9 therein and clamping it in place by retainer nuts 10 and 11threaded thereon, with a washer 12 interposed between nut 10 and panel5. Nut 10 could be an integral flange on shell 8. A liner sleeve 13,insulated from shell 8 by an insulator sleeve 14, is mounted within theshell 3 to constitute an inner section of the barrel, in which may bemounted a small electric lamp bulb 15. The insulator sleeve 14 may be atight fit within shell 8 and liner 13 may in turn be tightly fittedwithin sleeve 14 and thereby supported.

Head 7 includes a lens cap 16 which forms part of an assembly includinga tubular neck 17, externally threaded and mounted in barrel 6 bythreading it into liner sleeve 13 as shown. The metal base cartridge 18of lamp 155 is received in neck 17, with its base flange 19 hearingagainst the end of neck 17 and its end contact 20 engaged against acenter contact 21 in barrel 6. Properly insulated from the other partsof barrel 6 by any Well known conventional mounting, contact 21 projectsthrough the end of the barrel and is attached to a terminal 22. By anequally well known arrangement, a terminal 23 is connected to barrelliner 13' and projects through the end of the barrel while beinginsulated from shell 8.

Lens cap 16 includes a cylindrical skirt 24 which, in the assembledlight, abuts the end ofv barrel 6. An insulator sleeve 26 is threadedinto annular shoulder. 25' and is threaded onto neck 17 and interposedbetween shoulder 25 and neck 17', to insulate the latter from shell 8and head 7. The assembly including cap 16, insulator sleeve 26, neck 17and lamp bulb 15, 18, constitute the assembly referred to as head 7which can be mounted in barrel 6 by threading neck 17 into liner sleeve13 as above stated. The end of skirt 24 is formed inwardly to provide aretainer flange 27. A lens 28 having a rim 29 of reduced thickness,defining a shoulder that is retained beneath flange 27, is spring loadedby a marcelled washer spring 30 into frictional engagement with theunderside of flange 27. Spring 30 is interposed under compressionbetween shoulder 25 and lens 28 and is of larger diameter than the lightaperture defined by the opening at the outer end of neck 17. Suitablyapplied to lens 28 in any known manner (as by recessing its outer face)is an indicating character such as the arrow 31 shown in Fig. 2. Theindicating character can as well be a letter, numeral, or word.

By applying the tip of a finger or thumb against lens 28 and pressinginwardly, the frictional engagement of rim 29 against flange 27 isbroken and the lens may then be easily rotated by turning the finger,the frictional engagement of the finger against the lens beingsuflicient to efiect such rotation. When the lens is released, thespringloaded frictional engagement of rim 29 against flange 27,functioning as a brake, locks the lens in its adjusted position,elfectively resisting any tendency of the lens to rotate under theeffect of vibration.

In the form of the invention shown in Fig. 4, head 7a embodies adiffusion disc 32, of translucent material, with indicia 31 imprintedthereon, inserted into a shallow circular recess in the inner side oflens 28a, and marcelled spring washer 30 may bear against this disc. Theparts 28a, 32 and 30 are mounted within a retainer flange 24, 27 on askirt 25a corresponding generally to the parts 24, 25 of Fig. 1 but ofmodified cross section as shown.

One of the primary objects of the invention is to facilitate theassembly of thread-connected parts in a small indicator light wherein itis impossible to determine in advance the exact position of rotation atwhich the lens head will stop when it is being screwed into the bandassembly. With a pre-assembled jewel having such a directionalorientation requirement, the likelihood of the legend being properlyoriented at the exact point Where the head has been screwed snugly homein the barrel, is quite negligible if the lens is fixed against rotationin the lens cap. The invention makes it possible to install the light'without regard to the position that will be assumed by the lens whenthe installation is completed, and to then rotate the lens within itscap until it is adjusted to its correct position.

The indicating device 31, as shown in Fig. 2, may be regarded either asan arrow or the letter A. Any other letter, or a numeral could as wellbe utilized.

I claim:

In an indicator lamp, a lamp barrel for housing a lamp bulb; a lens capincluding a cylindrical skirt, a flange projecting inwardly from theouter end of said skirt and defining a lens aperture; means extendinginwardly from the rear end of said skirt and joining the same to saidbarrel, said means defining a forwardly facing annular shoulder; a lensreceived in said cap, said lens having a circular rim disposed behindsaid flange and a central lens body provided with an indicatingcharacter having a function affected by rotary orientation; and anannular compression spring of marcel shape interposed between said lensrim and said shoulder under compression and yieldingly loading said lensrim into frictional holding engagement with the rear surface of saidflange for normally holding said lens in a selected position of rotaryadjustment from which said lens may be adjusted by subjecting it tofingertip pressure to depress it so as to release said holdingengagement, followed by rotation applied to the lens through thefingertip while said holding engagement remains released, the highpoints of said spring engaging said lens rim with a limited area ofcontact so as to provide for relatively free rotation of the lens whensaid frictional engagement is released.

References Cited in the file of this patent UNITED STATES PATENTS

